Spray means for dishwasher



Jan. 9, 1968 D. L. CLAR-K 3,362,645

SPRAY MEANS FOR DISHWASHER Fil ed Oct. 22, 1965 PRIOR ART FIGZ INVENTOR. DAVID L. CLARK BYW H15 ATTORNEY United States Patent 3,362,645 SPRAY MEANS FOR DISHWASHER David L. Clark, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Oct. 22, 1965, Ser. No. 501,561 6 Claims. (Cl. 239-251) ABSTRACT OF THE DISCLOSURE Spray means for an automatic dishwasher comprising an elongate hollow casing supported in the dishwasher wash chamber for rotation about an axis transverse to the length of the casing. Fluid is admitted to the casing under pressure through an inlet adjacent the axis of rotation and a plurality of longitudinally spaced orifices in the casing issue the fluid into the wash chamber. A passageway in the casing conducts the fluid to the orifice farthest from the axis of rotation before conducting it to the orifices which are closer to the axis of rotation.

This invention relates generally to automatic dishwashers and, more particularly, to an improved spray means for an automatic dishwasher.

In most automatic dishwashers commercially available today, washing of dishes or other articles is effected by generating a vigorous spray of wash fluid, e.g., water and detergent solution, within a wash chamber containing the dishes. Ideally, the wash fluid would be distributed so as to subject each article to substantially the same wash action as other articles of like nature. One important factor in making up wash action is the quantity of fluid applied to the articles so that ideally an equal quantity of fluid would be applied to each article. In practice, this ideal has been diflicult to achieve and, therefore, the approach has been to assure that each article has at least a minimum quantity of fluid applied thereto. In systems heretofore available this approach resulted in ineflicient use of fluids since many articles were being subjected to unnecessarily large quantities of fluid.

To further explain the problem, most dishwashers available today have a spray device supported for rotary movement about an axis of rotation transverse to the longitudinal axis of the spray device. A plurality of orifices are spaced along the device and wash fluid, fed into the device under pressure by a pump, issues from the orifices to generate a vigorous spray directed to impinge upon the articles being washed. The individual orifices, being spaced from each other, are at different distances from the axis of rotation. All orifices travel in an arcuate path as the device moves. Those at a greater distance from the axis of rotation travel a larger arcuate path than those closer to the axis. As a result, they also cover a larger area of the wash chamber during their travel. Since more area is covered by those orifices farther from the axis of rotation, it would be desirable to issue a greater quantity of water per unit time therethrough. Spray devices heretofore available, however, position these orifices farther from the source of wash fluid, i.e., the inlet to the spray device, than those orifices travelling a smaller path. As the wash fluid passes an orifice in the spray device it experiences a pressure drop so that by the time the fluid reaches those orifices travelling the largest arcs, the pressure is significantly depleted. The present invention provides means to overcome the afore-described problem.

Accordingly, it is an object of this invention to provide an improved spray means for an automatic dishwasher.

Briefly stated, in accordance with one aspect of the present invention, there is provided a spray means for the wash chamber of an automatic dishwasher having an elongated hollow casing supported for rotary movement about an axis transverse to the longitudinal axis of the casing. An inlet admits fluid into the casing under pressure and a plurality of orifices in the casing issue the fluid into the wash chamber to generate a wash action. A passageway within the casing conducts the fluid to the orifice most remote from the axis of rotation before conducting it to orifices less remote from the axis of rotation.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings, in which:

FIGURE 1 is an elevational view, partially cut away to show details, of an automatic dishwasher employing the present invention;

FIGURE 2 is a partial sectional view of a prior art spray device;

FIGURE 3 is a sectional view of a spray device of the present invention; and

FIGURE 4 is a modified form of the spray device of the present invention.

Referring now to the drawing, and particularly to FIG- URE 1, there is illustrated an automatic dishwasher 10 having an outer cabinet 11 with a wash chamber 12 therein. Access to wash chamber 12 is provided by a door 13 pivotally secured to cabinet 11 by hinge 14. Disposed within wash chamber 12 are dish supporting racks 15 and 16 which are adapted to support articles to be washed within wash chamber 12.

Bottom Wall 17 of wash chamber 12 has a centrally depressed portion forming a sump 18. Disposed within the central portion of sump 18 and supported by bottom wall 17 is a motor-pump assembly 19. Motor-pump assembly 19 includes an electrically-reversible motor 20 and a pump 21. Pump 21 has an inlet (not shown) which is adapted to withdraw fluid from sump 18 and, in one direction of rotation of motor 20, propel the fluid out through an efiluent discharge conduit 22 and, in the other direction of rotation of motor 20, propel the fluid upwardly under pressure into a spray device 23. Spray device 23 is supported by pump 21 in any suitable manner so that it is free to rotate about an axis transverse to the longitudinal axis of spray device 23. As it rotates, wash fluid issues from orifices 24 upwardly into wash chamber 12 to generate a wash action upon articles supported by racks 15 and 16.

All of the afore-described elements of dishwasher 10 are substantially conventional and, may be substantially modified from the exact relationship shown without seriously affecting the present invention.

As mentioned above, as spray device 23 rotates, and wash fluid is issued from orifices 24 to effectuate a wash action within chamber 12, the orifice adjacent the distal end of device 23 travels farther than any of the remaining orifices. Because it travels a larger path, it covers a larger area within wash chamber 12 and, it would therefore be desirable, to at least assure that suflicient fluid is present at that orifice with sufficient pressure to effectuate the desired wash action in wash chamber 12 above the path that the orifice travels. In the prior art devices, as shown in FIGURE 2, the orifices which travel the larger path are conventionally placed farther from the fluid inlet 25. The fluid passing from inlet 25 through the device 23 experiences a pressure drop as it passes each orifice 24. Accordingly, the fluid reaches the last orifice, and in the prior art the orifice travelling the larger path, at substantially less pressure than present at inlet 25. To help overcome this shortcoming, some prior art devices reduce the cross sectional area of the interior of the device 23 along a the path of flow; however, this has not provided a complete solution to the problem.

In accordance with the present invention, there is illustrated in the embodiment of FIGURE 3, an improved spray means 26 having an inlet 27 formed in an elongated hollow casing 28. A plurality of orifices 29 are provided in a wall of casing 28 to allow wash fluid to issue from casing 28 into the wash chamber of an automatic dishwasher. Within casing 28 is a generally U-shaped passageway 30 having a first leg 31 and a second leg 32. Wash fluid is admitted under pressure into casing 28 through inlet 27. A partition or barrier 33 defines the U-shaped passageway 30 and directs the flow of fluid as indicated by the arrows in FIGURE 3.

Casing 28 is adapted to rotate about an axis indicated by point 34 which, in the preferred embodiment of the present invention, is concurrent with the center of inlet 27. As can be seen from FIGURE 3, the one orifice of the plurality of orifices 29 which is most remote from the axis of rotation is the orifice which is the first to receive fluid from inlet 27 or, in other words, is in closest fluid-receiving relationship with inlet 27.

FIGURE 4 illustrates a modification of the spray means 26 of FIGURE 3. The spray means 35 of FIGURE 4 includes an elongated hollow casing 36 defining a generally U-shaped passageway 37 therein. A plurality of orifices 33 extend through casing 36 to serve the same function as orifices 29 of spray means 26 in FIGURE 3. Wash fluid enters casing 36 through an inlet (not shown) and follows the path illustrated by the arrows in FIGURE 4. Casing 36 is adapted to be mounted for rotation about an axis indicated by point 39. Once again, it should be obvious that the flow path in casing 36 is such that the one of the plurality of orifices 38 most remote from the axis of rotation is the first to receive wash fluid from the inlet.

In each of the spray means illustrated in FIGURES 3 and 4, the passageway defined by the casing is configurated to conduct wash fluid to the individual ones of the plurality of orifices in a sequence inverse, respectively, to the distances between the individual orifices and the axis of rotation. This results in the fluid-receiving relationship of the plurality of orifices through the passageway being inverse to the spatial relationship of the orifices to the axis of rotation of the spray means.

Although the foregoing description sets forth the present invention by describing the preferred embodiments, it should be realized that a spray means may be provided which extends in opposite directions from the axis of rotation and from the wash fluid inlet. In other Words, it is not critical that the spray means be entirely disposed in a single direction from the axis of rotation. Moreover, although it would depart from the ideal, it is also within the spirit of the present invention to provide one or more orifices in leg 31 of spray means 26 as long as the majority of orifices are disposed in more remote fluid-receiving relationship to the inlet than is the orifice most remote to the axis of rotation.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of construction of the examples illustrated, and it is contemplated that other modifications or applications will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Spray means for an automatic dishwasher comprising:

(a) an elongated spray arm mounted for rotation within said dishwasher about an axis generally perpendicular to said spray arm,

(b) an inlet to admit Wash fluid under pressure into said spray arm,

(c) a plurality of orifices in said spray arm from which the wash fluid issues to generate a wash action within the dishwasher, and

(d) a passageway within said spray arm to conduct the wash fluid from said inlet to said plurality of orifices,

(c) said orifices being spaced from each other at diiferent distances from said axis and generally in a common plane substantially perpendicular to said axis;

(f) said passageway being configurated to conduct the wash fluid to the one of said plurality of orifices most remote from said axis before conducting it to the ones of said plurality of orifices less remote from said axis.

2. Spray means for an automatic dishwasher comprising:

(a) an elongated spray arm,

(b) means to mount said spray arm for rotary move ment about an axis transverse to said spray arm, (0) an inlet to admit wash fluid under pressure into said spray arm,

(d) a plurality of orifices in said spray arm from which the wash fluid issues to eifectuate a wash action with in the dishwasher, and

(e) a passageway within said spray arm to conduct the wash fluid from said inlet to said plurality of orifices,

(f) said orifices being spaced along said passageway at different distances from said axis and generally in a common plane substantially perpendicular to said axis,

(g) said passageway being configurated to conduct wash fluid to the individual ones of said plurality of orifices in a sequence inverse respectively to the distance between said indiivdual ones of said plurality of orifices and to said axis.

3. A spray device to effectuate a wash action within the wash chamber of a dishwasher comprising:

(a) a hollow elongated casing,

(b) means to mount said casing for rotary movement about an axis transverse to said casing,

(c) an inlet to admit wash fluid under pressure into said casing,

(d) a plurality of orifices in said casing through which the wash fluid passes to create a Wash action Within the wash chamber, and

(e) a passageway within said casing in fluid-receiving relationship to said inlet,

(f) said plurality of orifices being generally in a com mon plane substantially perpendicular to said axis and in fluid-receiving relationship with said passagey,

(g) the fluid-receiving relationship of said plurality of orifices to said passageway being inverse ito the spatial relationship of the orifices to said axis.

4. A spray device to generate a wash action within the wash chamber of a dishwasher comprising:

(a) a hollow elongated casing,

(b) a generally U-shaped passageway defined within said casing and having first and second legs,

(0) an inlet to admit wash fluid under pressure to the end of said first leg most remote from said second leg, and

(d) a plurality of orifices in said casing to issue wash fluid from said passageway to create a wash action within the wash chamber,

(e) said plurality of orifices being spaced from each other along said passageway,

(f) the one of said orifices having the closest fluidreceiving relationship with said inlet being adjacent the end of said first leg most remote from said inlet with the remainder of said plurality of orifices being spaced along said second leg. i

5. A spray device to generate a wash action within the Wash chamber of a dishwasher comprising:

(a) a hollow elongated casing,

(b) means to support said casing for rotary movement about an axis transverse to said casing,

(c) a passageway within said casing,

(d) an inlet to admit wash fluid under pressure into said passageway, and

(e) a plurality of orifices in said casing generally in a common plane substantially perpendicular to said axis to receive wash fluid from said passageway and issue it into the wash chamber to generate a washing action therein,

(f) each of said plurality of orifices defining a distinct arcuate path upon movement of said casing about said axis,

(g) the one of said plurality of orifices defining the arcuate path of greatest radius being in closer fluidreceiving relationship with said inlet than the remainder of said plurality of orifices.

6. A spray device to generate a wash action within the wash chamber of a dishwasher comprising:

(a) a hollow elongated casing mounted for rotation in a dishwasher about an axis generally perpendicular to the casing length,

(b) a generally U-shaped passageway defined within said casing and having a first leg extending generally outward from said axis and a second leg returning generally toward said axis,

(c) an inlet to admit wash fluid under pressure to the inner end of said first leg, and

(d) a plurality of orifices in said casing to issue wash fluid from said passageway to create a wash action within the wash chamber,

(e) said orifices including an orifice adjacent the outer end of said first leg,

(f) the majority of said orifices being spaced along said second leg and thereby being in a more remote fluid receiving relationship to said inlet than said orifice adjacent the outer end of said first leg.

References Cited UNITED STATES PATENTS 462,902 10/1891 Jones 239258 20 M. HENSON WOOD, 111., Primary Examiner.

V. M. WIGMAN, Assistant Examiner. 

